SOLUTION: How much is the difference in the sale price if a 20% off coupon is used first and then a 25% off coupon is used versus using the 25% off coupon first and then the 20% off coupon?

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Question 251903: How much is the difference in the sale price if a 20% off coupon is used first and then a 25% off coupon is used versus using the 25% off coupon first and then the 20% off coupon?
Answer by richwmiller(17219) (Show Source):
You can put this solution on YOUR website!
let the cost of the merchandise equal x
First of all,
I know of no stores that allow use of two coupons on one product so this exercise is moot( useless).
You might have store discount (sale price) and a coupon at the same time.
At any rate for math fun, let's act as if this is a real problem.
.20x is the discount
and .80 is the price after the discount
.25x is the discount
and .75x is the price after the discount
so in the first case we have
.80x and on top of that 25 %discount
so we now have .75(.80x)
in the second case we have
.75x and on top of that 20 % discount
.80*.75x
let's compare
.75*(.80x) vs .80*(.75x)
They are identical since .75*.80 =.80*.75=.60=60%
.75*.80=(3/4)*(4/5)=3/5=60%
.80*.75=(4/5)*(3/4)=3/5=60%
That is 40% discount where we pay only 60% of the original price.
It does make a difference if you have $10.00 off coupon and also 20%
discount.
Since the 10 dollars doesn't change it makes a difference where it is applied.
Let's say we have 20% off store sale and a 10.00 off coupon. original price $100.00
If we do the 20% off first
.80*100=80 now take away the 10 dollars=70 dollars
if we take the 10 dollars off first
100-10=90
.80*90=72
72 does not equal 70
So there is a difference in applying discounts but not two percentage discounts.